The following is a Pilot Report from Lazair flying enthusiast, Robert Chapman. He received a rare glimpse into the actual flying qualities of the newly designed and flying, eLazair, built by Dale Kramer. The report was originally detailed out on www.rcgroups.com –
“I have been a Lazair enthusiast, builder and owner for the past 30 years. This last weekend I had the good fortune to fly Dale Kramer’s amphibian Series 3 that he has chronicled the conversion to electric propulsion right here in this blog. Dale and Carmen made the offer to me to fly it at the conclusion of AirVenture at Oshkosh, Wisconsin this Summer (where they received an unprecedented two awards from the Experimental Aircraft Association). Schedules, and then a severe head and chest cold scuttled my plans to visit during the above mentioned Seaplane Homecoming Event in Hammondsport. Dale indicated that he needed to remove his Lazair from the lake by the end on September, so my wife and I high-tailed it there from our home in Virginia Friday morning. We arrived in New York as a humongous low pressure system proceeded to park itself over the state – and several surrounding ones.
I have flown virtually every model and variation of the Lazair over the years. Engines include the 99cc chainsaw motor (both direct propeller drive and my own prop-speed reduction versions), 185cc Rotax (with bi-blade and long blade props) and a couple different twin cylinder engines. Aircraft weights ranged from not much over 150 pounds to around 350. Dale’s conversion, for reference, weighs around 400 pounds with the float gear installed! So you can imagine my anticipation in doing a comparison to my past experience flying these planes with their 2-stroke engines.
And the comparison IS quite interesting. Other than the “barking” sound at start-up while the sensorless Joby motor and the motor, controller try to communicate and play nice, the smoothness and linear throttle control is quite satisfying. Actually, the start-up ruckus of the electrics only lasts a second and is light years better – insignificant – compared to the normal, obnoxious 2-stroke engine start-up/cold idle/ warm up routine. I had watched Dale fly numerous times at AirVenture along with countless times on YouTube videos but I was still unprepared for the level of performance that I experienced. I truly didn’t expect the short take-off, nice climb, and speedy cruise speeds of this plane fitted on the huge, heavy seaplane gear. All the while the smooth running Joby motors never sounded the least bit stressed, and motor temps seemed ridiculously low when you consider how small the motors appear. Within a few minutes I was totally comfortable with the electrics despite the winds aloft. The motors ran super smoothly and responded to throttle settings perfectly. Soon I was totally relaxed and running through a variety of maneuvers. Of special note to me was how strongly the motors pulled on take-off, and yet at high cruise speeds the motors never let the props unload; something that is very hard to produce when using 2-stroke engines with their narrow power bands. I think that is one reason this plane performs as well as it does with only these two small motors. A word to best describe the conversion may be synergy – this marriage of airframe and electric motors works very well. This thing I was flying was a very happy machine! I found myself content to just cruise the lake shore at 3000 rpm reminiscing of the flights I made 30 years ago in Canada floating along the lake shore by Dale’s home there in what was then, I believed, a ground breaking Ultralight aircraft. Actually, I found myself rather overwhelming in an emotional way. Sometimes I forget what an impact the Lazair has had on my life.
Too soon the dual voltmeters indicated that the battery packs had sagged to 57 volts (at cruise power) – the point at which I had been directed to begin planning my landing. As much as I wished to continue this flight, even as I fought back the shakes from the cold that permeated my outfit, we swung a large descending turn out over the lake and back. When parallel to the shore near Dale’s dock, and facing into the wind, I reduced power to 1200 rpm for the final decent. The heavy craft sank somewhat faster than I had anticipated and, running out of control authority at the last instant, we arrived with a solid splash. No damage – except to my pride! The twin motors, generally unappreciated for their merits by Ultralight pilots, proved to be brilliant when maneuvering this small seaplane on the rough water. The electrics, with their ability to shut down and then restart almost instantly, made taxiing about the lake childs play. Very Cool. Despite not trying in the least to maximize flight endurance, recharging the packs indicated 20% charge still remained. My flight had lasted 35 minutes.
This conversion of Dale’s venerable Ultralight design stunned me by its level of refinement. While others have produced prototype after prototype, Dale has produced a sophisticated product level set-up the first time out. I should not have been surprised. The same mind conceived and designed both!”
-Bob Chapman (Chappy)